How it works
At the heart of BreezyPacks are materials called phase change materials, or PCMs.
The PCM absorbs and releases energy as it changes phase – this might sound complicated, but that’s exactly what ice does: It requires energy to melt, which it takes from the environment, cooling it in the process. It then gets rid of this excess energy when it freezes – which starts happening the moment it goes under 0°C / 32°F.
Our PCM has some practical differences compared to ice:
- It freezes at 27°C / 80°F.
This means that there’s no need for a freezer – it can freeze at room temperature.
It also means that it’s perfectly suited to keep your medication below 30°C.
- It lasts much longer than ice.
Ice melts much faster at a hot environment than, say, in the fridge – that’s because the rate of melting is related to how far it is from it’s melting point. Since our PCM’s freezing point is much significantly higher than that of ice, it lasts much longer than ice in a hot environment.
But, just like ice can turn into water and back an infinite number of times, so does our PCM – it does not degrade in the transition and can theoretically last forever.
How it’s built
The PCM in the BreezyPacks is encased in metallicized polymer bags – similar to Mylar® bags, in relatively high thickness. These bags are very resistant and practically leak-proof, and they’re contained in special pockets in the lining of the pack. You do not need to see or interact with them while using the product.
Another component that you will not see is the insulating layer, made using recycled felt, that helps your BreezyPack last longer in the heat.
All this is wrapped in linen canvas – which is both very durable and environmentally friendly, requiring less water and pesticides to grow than cotton. We believe that these details do matter.
How it’s tested
The development of BreezyPacks started on a piece of paper, with theoretical heat transfer calculations and chemical formulas.
After that comes lab testing – When we introduce new models and before each production run, a sample is brought into our lab and tested in a variety of conditions. 2-4 sensors check the temperature change in different areas of the pack at 1-minute intervals, with additional sensors outside of the pack, in the temperature-controlled testing setup.
We check how long it lasts, how hot can it stand, if it regenerates fast enough and a variety of other factors – It can be surprising how much thought has to go into such a simple looking product!
We also do continuous quality control – each batch of active material is melted and tested for uniformity, and each product is inspected for leaks or other issues after assembly.
The last phase is being attentive to comments our users: Every comment or issue with a product that a client reports is passed on to our lab team, and we continuously try to improve our products and develop new models to answer your needs.